821
FXUS65 KBYZ 081850
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1250 PM MDT WED JUL 8 2026
KEY MESSAGES
- SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING. A FEW STORMS
COULD BE SEVERE AND PRODUCE HAIL, STRONG WINDS, AND HEAVY RAIN.
- TRENDING DRIER THURSDAY; A CHANCE OF THUNDERSTORMS OVER THE EAST
AND SOUTH.
- RECORD HOT THIS WEEKEND INTO EARLY NEXT WEEK! HIGH TEMPERATURES
WILL EXCEED 100 DEGREES MOST LOCATIONS OVER THE WEEKEND, AND
TEMPS ON SUNDAY MAY CHALLENGE ALL-TIME RECORDS.
DISCUSSION
NEXT 7 DAYS...
A WEAK SHORTWAVE TROUGH IS FORECAST TO MOVE THROUGH MONTANA THIS
AFTERNOON BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. THIS
WAVE OF ENERGY IS NOT FORECAST TO BE TOO STRONG AND THUS A
MAJORITY OF STORM INITIATION SHOULD OCCUR OVER THE MOUNTAINS,
ESEPCAILLY THOSE CLOSER TO THE MT/WY STATE LINE. THE INITIAL PUSH
OF MID TO UPPER LEVEL LIFT TRIES TO PUSH THROUGH ON THE EARLIER
SIDE TODAY PUTTING MOST OF THE FORECAST AREA UNDER BROAD
SUBSIDENCE BY 00Z. SOME MODELS DO PUSH THROUGH ANOTHER, EVEN
WEAKER, VORT MAX JUST AFTER 00Z WHICH COULD PROVIDE ENOUGH LIFT
IN CONJUNCTION WITH THE TERRAIN TO INITIATE ANOTHER ROUND OF
CONVECTION.
IN TERMS OF CONVECTIVE/SEVERE INGREDIENTS, THE SHEER IS NOT
OVERLY IMPRESSIVE. THE RAP/NAM MODELS SHOW A BROAD AREA OF 30KTS
OF EFFECTIVE BULK SHEAR OVER EASTERN MT/WY THIS AFTERNOON AND
EVENING WITH LOCALIZED HIGHER POCKETS. 30KTS IS ENOUGH TO SUSTAIN
SOME CONVECTION WITH WIDELY ISOLATED SEVERE CONVECTION POSSIBLE.
MOISTURE IS ACTUALLY PRETTY GOOD FOR THIS REGION AS OBSERVED DEW
POINTS ARE ALREADY IN THE 50S TO LOW 60S F WHICH SHOULD BE PLENTY
FOR ANY STORM TO WORK WITH. MID LEVEL LAPSE RATES WIL BE IN EXCESS
OF 7-8 C/KM THIS AFTERNOON AND EVENING ACROSS THE REGION OF
INTEREST WITH EVEN HIGHER VALUES THE FARTHER SW YOU GO. THE MAIN
LIMITING FACTOR TO CONVECTION TODAY APPEARS TO BE THE PRESENCE OF
A CAPPING INVERSION. WITH HIGH TEMPERATURES TODAY FORECAST IN THE
90S THIS SHOULD BE ABLE TO BE OVERCOME, HOWEVER SOME MODELS SHOW A
STRONGER CAP THAN OTHERS. THE LACK OF SHEAR AND THE RELATIVELY
STRAIGHT HODOGRAPH SHAPE MAY PREVENT ANY STORM FROM GETTING TOO
STRONG, HOWEVER THE INVERTED-V TYPE SOUNDINGS AND MODEST CAPE IN
THE HAIL GROWTH ZONE COULD CERTAINLY SUPPORT AN ISOLATED SEVERE
STORM LATER TODAY.
THURSDAY COULD BRING ANOTHER CHANCE FOR SCATTERED SHOWERS AND
THUNDERSTORMS MOSTLY ALONG AND SOUTH OF THE MT/WY STATE LINE.
THESE STORMS ARE NOT EXPECTED TO BECOME SEVERE. WIDELY ISOLATED
SEVERE STORMS ARE POSSIBLE HOWEVER, OVER EXTREME SOUTHEAST MT AND
INTO SD.
THE BIG STORY REMAINS THE POTENTIALLY RECORD BREAKING HEAT IN
STORE FOR THIS WEEKEND. LONG RANGE MODELS AND THEIR ENSEMBLES ARE
CONSISTENT IN DEVELOPING A STRONG RIDGE OVER THE HIGH PLAINS IN
THE COMING DAYS. ON SATURDAY, BOTH THE ECMWF AND GFS ENSEMBLES
BRING 594 DM 500MB HEIGHTS INTO THE REGION WITH THOSE INCREASING
TO 597 DM HEIGHTS SUNDAY. THIS ALONE WOULD SIGNAL THE HOTTEST
TEMPERATURES OF THE SEASON. DETERMINISTIC ECMWF AND GFS 700MB
TEMPERATURE VALUES ARE AROUND 18-20C FOR SATURDAY AND 20-22C FOR
SUNDAY. THIS TRANSLATES TO TEMPERATURES AT LEAST NEAR 100F
SATURDAY AND IN EXCESS OF 100F SUNDAY. THERE HAVE BEEN SOME MODEL
RUNS SHOWING HIGHER VALUES AT 700MB IN ADDITION TO THE 35-40C
850MB TEMPERATURES POSSIBLE.
WHILE THE NBM WAS A TOUCH TOO HIGH WITH HIGH TEMPERATURES DURING THE
JUNE HEAT WAVE, THE DETERMINISTIC NBM SHOWS MOST OF OUR CLIMATE
SITES APPROACHING OR ECLIPSING OUR ALL TIME RECORD HIGHS SUNDAY
WITH TEMPS OVER 110F NOT OUT OF THE QUESTION.
WITH SOARING TEMPS AND MINIMAL TO NO MOISTURE ADVECTION LOW TO
VERY LOW RH VALUES ARE FORECAST THIS WEEKEND AS WELL. MIN RH
VALUES IN THE TEENS ACROSS THE REGION WITH SINGLE DIGITS IN AND
NEAR WY ARE FORECAST DURING THE PARTICULARLY HOT DAYS OF SATURDAY
AND SUNDAY. THE "GOOD NEWS" IS THAT THERE WILL ALSO BE VERY
LITTE WIND WITH THIS HEAT WHICH SHOULD KEEP FIRE CONCERNS LOWER
THAN THEY COULD BE. AS WE LOOK AHEAD INTO NEXT WEEK THOUGH THERE
IS A SIGNAL FOR THE POTENTIAL FOR SOME BREEZY CONDITIONS TO MAKE
AN APPEARANCE.
SPEAKING OF NEXT WEEK, ENSEMBLES KEEP THE TEMPERATURES ABOVE
AVERAGE FOR THE ENTIRETY OF NEXT WEEK. THE GFS ENSEMBLE ACTUALLY
SHIFTS THE RIDGE AXIS TO THE WEST AND CENTERS IT NEARLY OVER OUR
CWA WHICH WOULD KEEP HIGH TEMPERATURES IN THE UPPER 90S TO NEAR
100F IN BILLINGS NEARLY EVERY DAY.
IT IS IMPORTANT TO TAKE PRECAUTIONS WITH HEAT LIKE THIS.
TEMPERATURES NEVER BEFORE RECORDED IN THIS REGION ARE POSSIBLE ON
SUNDAY. AVOID THE OUTDOORS DURING THE AFTERNOON AND SPEND AS MUCH
TIME AS POSSIBLE IN AIR CONDITIONING. BE SURE TO FREQUENTLY CHECK
ON THOSE MORE AT RISK IN THE HEAT, SUCH AS THE ELDERLY OR THOSE
WITH CHRONIC HEALTH RISKS. THE DANGER OF THE HEAT DOES NOT END
WITH SUNSET. LOW TEMPEATURES FORECAST IN THE 70S FOR MUCH OF THE
REGION SUN/MON AM DOES NOT GIVE THE BODY A CHANCE TO COOL DOWN.
ADDITIONALLY, THOSE LOCALITIES IN/NEAR CITIES ARE LIKELY TO STAY
HOTTER THROUGH THE OVERNIGHT PERIOD DUE TO THE URBAN HEAT ISLAND
EFFECT. REMEMBER THAT EXTREME HEAT IS THE NUMBER ONE WEATHER
RELATED KILLER.
BELOW ARE THE ALL-TIME RECORD HIGH TEMPERATURES AT EACH OF OUR
CLIMATE STATIONS:
BILLINGS, MT 108F
LIVINGSTON, MT 105F
MILES CITY, MT 111F
SHERIDAN, WY 107F
BAKER, MT 109F
WMR
AVIATION
18Z DISCUSSION...VFR CONDITIONS WILL PREVAIL OUTSIDE OF
CONVECTIVE ACTIVITY THROUGH THURSDAY MORNING. ISOLATED
THUNDERSTORMS, WITH FAIRLY HIGH BASES (~8-10KFT AGL) ARE EXPECTED
FOR MOST OF THE AREA THIS AFTERNOON AND EVENING, WITH MORE
SCATTERED ACTIVITY ALONG THE SOUTHERN STATE LINE ZONES.
KBIL/KMLS/KSHR TAF LOCATIONS HAVE PROB30 GROUPS TO ACCOUNT FOR
THIS ACTIVITY. THERE IS A TEMPO FOR KLVM THIS AFTERNOON FOR
CONVECTIVE WIND GUSTS FUNNELING NORTH ALONG THE YELLOWSTONE RIVER
AND IMPACTING THE TERMINAL AT TIMES THIS AFTERNOON (20-23Z). WIND
GUSTS AROUND 40KTS CAN BE EXPECTED WITH EVEN LIGHTER CONVECTION,
AND A FEW GUSTS OVER 50KTS CAN'T BE RULED OUT WITH STRONGER CELLS.
BRIEF MVFR CONDITIONS CAN BE EXPECTED NEAR PRECIPITATION AREAS.
CONVECTION SHOULD DISSIPATE BY 06Z. CHAMBERS
PRELIMINARY POINT TEMP/POPS
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 061/092 063/097 065/104 069/107 072/096 071/095 068/094
21/U 02/T 10/G 00/G 00/U 11/U 32/T
LVM 053/090 055/093 057/102 061/101 062/094 062/091 059/090
31/U 01/U 00/G 00/G 01/U 13/T 44/T
HDN 059/092 061/097 064/104 067/109 070/098 069/097 067/097
20/U 01/U 10/G 00/G 00/U 11/B 32/T
MLS 061/092 061/098 066/104 070/108 073/098 068/096 068/096
21/U 02/W 10/G 00/G 00/U 11/B 22/T
4BQ 061/091 061/096 066/104 070/106 075/098 070/097 068/095
22/T 21/U 20/G 00/G 00/U 01/U 22/T
BHK 057/089 057/094 062/100 065/104 070/098 064/094 063/092
23/W 11/U 20/U 00/G 00/U 11/U 22/T
SHR 055/088 056/094 060/102 064/105 067/097 065/095 063/094
33/T 22/T 00/G 00/N 00/U 02/T 33/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...EXTREME HEAT WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
LATE SUNDAY NIGHT FOR ZONES
29>34-36-37-40-42-56>58-63>66-138-139-141-169-170-172-173-228-235.
WY...EXTREME HEAT WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
LATE SUNDAY NIGHT FOR ZONE 199.
WEATHER.GOV/BILLINGS
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